Prediction of laminate damage processes using combined micro-mechanics, fracture mechanics and statistics approach

摘要

An engineering approach has been developed to predict composite laminate failure. ^Based on a previous study which analyzed fiber breakage in a single composite layer under high temperature and tension loads, this paper presents an extension of that work to multidirectional laminated composites and improvements in the previous analysis. ^The stiffness reduction of each layer is computed based on: (1) in the fiber direction, the calculated fiber failure ratio and composite fracture; (2) in the direction normal to the fiber, the estimated matrix cracking. ^The laminate property is affected by the stiffness reduction of each ply. ^The analysis consists of micromechanics, fracture mechanics and statistics principles to model and predict the mechanical response and failure mechanism of polymer and ceramic matrix composites. ^The technique uses experimentally derived empirical coefficients to account for the interface of fiber and matrix, fiber strength, and fiber-matrix stiffness reductions. ^Analytical results are generated for graphite-epoxy, Nicalon/CAS, and C/SiC and compared with experiments. ^(Author)